1. Important qualities.
In my opinion the most important quality in a job interview is the personality because you can empathize or not with the interviewer and this may be decisive. Also, I think the personality is a very important quality for almost all jobs. Appearance, qualifications and work experience are more or less important depending on the class of job.
2. Job interviews.
I had two or three job interviews but a long time ago, so I almost can’t remember them. I only remember they were a bad experience for me because I was very young and very nervous too, and when I’m nervous I exude a lot… It was a disagreeable experience for me and for the interviewer too, I think.
3. Job advice.
I think I’m not the most indicated person to give advices to anybody about a first interview job, or maybe yes. I only can give an advice: be calm and don’t wear too much dress by chance ;-)